ECU is picking up an intermittent or non-critical problem

Some vehicle problems may occur randomly or intermittently. The ECU may store a code, and detecting the problem is no longer there, remove the code. This can be an early warning sign of a developing problem. The problem is not severe, but some vehicle components are not functioning properly.

Table of Contents

• 1. Symptoms
  • 1.1 Check Engine Light Goes Off and On

Symptoms

Check Engine Light Goes Off and On

The "Check Engine" light, "Service Engine Soon" on some vehicles, is an indicator that a problem code has been stored in the vehicle's computer. If the code is retracted later, the light will go off. If the light repeatedly comes off and on, the problem may be occurring then not, causing the trouble codes to activate and deactivate.